[llvm-commits] [llvm] r48994 - in /llvm/trunk: lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/X86/pr2182.ll

[Dan Gohman]

Author: djg
Date: Mon Mar 31 15:32:52 2008
New Revision: 48994

URL: http://llvm.org/viewvc/llvm-project?rev=48994&view=rev
Log:
Fix a DAGCombiner optimization to respect volatile qualification.

Added:
    llvm/trunk/test/CodeGen/X86/pr2182.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=48994&r1=48993&r2=48994&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Mar 31 15:32:52 2008
@@ -4387,7 +4387,8 @@
   // value.
   // TODO: Handle store large -> read small portion.
   // TODO: Handle TRUNCSTORE/LOADEXT
-  if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
+  if (LD->getExtensionType() == ISD::NON_EXTLOAD &&
+      !LD->isVolatile()) {
     if (ISD::isNON_TRUNCStore(Chain.Val)) {
       StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
       if (PrevST->getBasePtr() == Ptr &&

Added: llvm/trunk/test/CodeGen/X86/pr2182.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pr2182.ll?rev=48994&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/pr2182.ll (added)
+++ llvm/trunk/test/CodeGen/X86/pr2182.ll Mon Mar 31 15:32:52 2008
@@ -0,0 +1,24 @@
+; RUN: llvm-as < %s | llc | grep {addl	\$3, (%eax)} | count 4
+; PR2182
+
+target datalayout =
+"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i386-apple-darwin8"
+ at x = weak global i32 0          ; <i32*> [#uses=8]
+
+define void @loop_2() nounwind  {
+entry:
+        %tmp = volatile load i32* @x, align 4           ; <i32> [#uses=1]
+        %tmp1 = add i32 %tmp, 3         ; <i32> [#uses=1]
+        volatile store i32 %tmp1, i32* @x, align 4
+        %tmp.1 = volatile load i32* @x, align 4         ; <i32> [#uses=1]
+        %tmp1.1 = add i32 %tmp.1, 3             ; <i32> [#uses=1]
+        volatile store i32 %tmp1.1, i32* @x, align 4
+        %tmp.2 = volatile load i32* @x, align 4         ; <i32> [#uses=1]
+        %tmp1.2 = add i32 %tmp.2, 3             ; <i32> [#uses=1]
+        volatile store i32 %tmp1.2, i32* @x, align 4
+        %tmp.3 = volatile load i32* @x, align 4         ; <i32> [#uses=1]
+        %tmp1.3 = add i32 %tmp.3, 3             ; <i32> [#uses=1]
+        volatile store i32 %tmp1.3, i32* @x, align 4
+        ret void
+}